Common variable immune deficiency
Common variable immune deficiency (CVID) is a disorder that impairs the immune system. People with CVID are highly susceptible to infection from foreign invaders such as bacteria, or more rarely, viruses and often develop recurrent infections, particularly in the lungs, sinuses, and ears. Pneumonia is common in people with CVID. Over time, recurrent infections can lead to chronic lung disease. Affected individuals may also experience infection or inflammation of the gastrointestinal tract, which can cause diarrhea and weight loss. Abnormal accumulation of immune cells causes enlarged lymph nodes (lymphadenopathy) or an enlarged spleen (splenomegaly) in some people with CVID. Immune cells can accumulate in other organs, forming small lumps called granulomas.Approximately 25 percent of people with CVID have an autoimmune disorder, which occurs when the immune system malfunctions and attacks the body's tissues and organs. The blood cells are most frequently affected by autoimmune attacks in CVID; the most commonly occurring autoimmune disorders are immune thrombocytopenia purpura, which is an abnormal bleeding disorder caused by a decrease in cell fragments involved in blood clotting called platelets, and autoimmune hemolytic anemia, which results in premature destruction of red blood cells. Other autoimmune disorders such as rheumatoid arthritis can occur. Individuals with CVID also have a greater than normal risk of developing certain types of cancer, including a cancer of immune system cells called non-Hodgkin lymphoma and less frequently, stomach (gastric) cancer.People with CVID may start experiencing signs and symptoms of the disorder anytime between childhood and adulthood; most people with CVID are diagnosed in their twenties or thirties. The life expectancy of individuals with CVID varies depending on the severity and frequency of illnesses they experience. Most people with CVID live into adulthood.There are many different types of CVID that are distinguished by genetic cause. People with the same type of CVID may have varying signs and symptoms.
Immunodeficiencies with predominantly antibody defects
Common variable immunodeficiency (CVID) comprises a heterogeneous group of diseases characterized by a significant hypogammaglobulinemia of unknown cause, failure to produce specific antibodies after immunizations and susceptibility to bacterial infections, predominantly caused by encapsulated bacteria.
Common variable immunodeficiency (CVID) comprises a heterogeneous group of diseases characterized by a significant hypogammaglobulinemia of unknown cause, failure to produce specific antibodies after immunizations and susceptibility to bacterial infections, predominantly caused by encapsulated bacteria. Prevalence is estimated at 1/25,000 among Caucasians and CVID affects men and women equally. While some patients are diagnosed with CVID in early childhood, the major peak of onset lies between the second and third decade of life, frequently with several years delay between onset and diagnosis. Over 98% of patients present with recurrent bronchitis, sinusitis, otitis and pneumonia, and chronic pulmonary damage is the major complication. About 25% of patients develop autoimmune phenomena; immune thrombocytopenic purpura (ITP) and autoimmune hemolytic anemia (AIHA) are the most common (see these terms). Lymphoproliferative disorders such as generalized lymphadenopathy and/or splenomegaly are present in up to 40% of patients, and there is an increased risk of developing gastrointestinal and lymphoid malignancies, especially non-Hodgkin's lymphoma (see this term). Up to 57% of patients develop bronchiectasis. CVID can be due to an intrinsic B cell defect (for example CD19-deficiency caused by mutations in CD19; 16p11.2), an intrinsic T cell defect (for example ICOS-deficiency caused by mutations in ICOS; 2q33), mutations in TNF receptors (such as TACI-deficiency or BAFFR-deficiency caused by mutations in TNFRSF13B and TNFRSF13C respectively; 17p11.2 and 22q13.1-q13.31) or without a genetic defect (see these terms). Other monogenic defects reported include MSH5, CD81 and CD20 deficiencies. Most cases are sporadic but about 20% are thought to be familial with either autosomal dominant (80%) or autosomal recessive (20%) inheritance. The prevalence of TACI-deficiency is estimated to be approximately 10%; the other defects are very rare. Patients with TACI-deficiency are more likely to be affected by lymphoproliferation and autoimmunity. There is considerable variation in the clinical presentation in patients with a similar genotype. Diagnosis should be suspected in patients with recurrent sinopulmonary infections exceeding an age-specific frequency, and is based on exclusion of other causes of hypogammaglobulinemia. Analyses of lymphocyte function, including analysis of specific antibody responses after vaccination, and immunophenotyping of T and B cells strengthen the diagnosis and indicate subgroups of CVID. Ultrasound and CT of the abdomen may be necessary to assess additional complications including enlarged abdominal lymph nodes, spleen and liver pathology or granulomas. Differential diagnoses include other causes of hypogammaglobulinemia including loss of gammaglobulins via the intestine or urine, hematological malignancies, viral infections or drug-induced loss of B-cell function. There is no curative therapy. Treatment is based on immunoglobulin replacement therapy, using pooled human immunoglobulin, usually administered intravenously or subcutaneously. To reduce long-term pulmonary sequelae, targeted antibiotic treatment is necessary. Patients with bronchiectasis may benefit from lung physiotherapy. The frequently occurring cytopenias require monitoring, and specific treatment such as splenectomy may be indicated. Concurrent autoimmune disorders or malignant disease require specific treatment. Patients with bacterial infections only have a better prognosis than patients with additional complications and can have nearly normal life expectancy, especially if diagnosis and treatment occurs soon after the onset of symptoms.
Structure of immune system (body structure)
Abbreviated Terms ICOS - [inducible costimulator] deficiencyCD19- [cluster of differentiation 40] deficiencyCD81 - [cluster of differentiation 81] deficiencyCD20 - [cluster of differentiation 20] deficiencyTACI - [transmembrane activator and calcium-modulating cyclophilin ligand interactor] deficiencyBAFF - [ B-cell activating factor] receptor deficiency
Related ICD 10 COde ICD 10 Code D83